Casing extension



Nov. 9 1926a E. V. CROWELL CASING EXTENSION Filed may 18, 1925 INVENTOR. 70 K Jranmfl BY f \i /u ATTORNEY.

Patented Nov. 9, 1926.

PATENT OFFICE.

ERD GROWELL, 0F LOS ANGELES, CALIFORNIA.

CASING EXTENSION.

Application filed May 18, 1925. Serial No. 31,017..

This invention is an extension for the casin of an oil and gas well adapted to extend into the oil sand below the standard casing, with a tight packing between the extension and the standard casing, so that gas cannot escape directly through the casing but is constrained to flow through the oil and thence into the casing extension for exerting an expulsive force in driving the oil from the sand into the well bore and lifting the oil from the bottom of the bore to the surface of the ground.

It is the object of the invention to provide a casing extension which may be introduced into the bore of the well after the standard casing has been lowered therein, and which is positively held against axial displacement in either direction while susceptible to ready removal when so desired,

It is a further object of the invention to provide for lowering the casing extension into the wellby a string of tubing which may be then left in the well for use as a conduit for the discharge of the fluid in accordance with standard practice.

Further objects of the invention will be readily understood from the following description of the accompanying drawings, in which:

Fig. 1 is a vertical section through the bore of a well, showing the casing extension in inoperative position as it is being lowered into the standard casing.

Fig. 2 is a similar view showing the casing extension in place in the well. v v

Figs. 3, 4, 5, and 6 areqtransverse sections on the lines indicated in Fig. 1. l a j Casing 1 of standard construction extend downwardly in the well bore 2 with a casing shoe 3 at its lower end below the waterstratum and above the oil sand and preferably resting upon the cap rock (not shown).

The extension for the standard casing includes aconnection whereby it is lowered into the casing by means of the usual well tubing, and packing means below said connection adapted'to form a tight-packing be.-

tween thecasing and its extension when the latter is in place, with a pipedepending from the packing into the oil sand below the casing shoe, and locking means on the packing ly to the cage 9.

structure for holding the parts against axial displacement in either direction until such time as it is desired to withdraw the casing extension from the well.

The means for lowering the casing extension by the usual string of well tubing comprises gudgeons 4 proyectingfrom opposite sides of a coupling collar 5 of the string of tubing 6, and a cage 9 connected at its; lower end 7 to the casing extension and having a bell mouth 8at its upper end.

Slots 10 for the passage of the gudgeons 4 open downwardly from, the upper end of the cage and terminate in circumferential slots 11 which are recessed at their upper sides in spaced relation from slots 10 as shown at 12.

In lowering the casing extension into the well it is mounted on the string of tubing 6 with cage 9 turned so that gudgebns 4. move through slots 10 and, 11 and seat in recesses 12. The weight of the casing extension is thus carried by the string of tubing and may be lowered to the desired level and fixed against axial displacement as herein-'- after described. The string of tubing is then lowered slightly to disengagegudgeons 4 from recesses 12, and the string of tubing is turned to move the gudgeons through slots 11 and into slots-10, so that the tubing may then be raised relative to the fixed casing extension, to clear coupling 5 from cage 9 and position the tubing at the desired level asshown in Fig. 2.

The packer for the casing extension comprises a shell 13 with a packing rubber 14 mounted thereon, andthe pipe 15 which ex= tends below the casing 1 into the oil sand depending from the shell. A slip. construction adapted to engage casing 1 and'hold the casing extension against downward movement is mounted on the packer shell between rubber 14 and pipe 15; and a second slip construction for engaging the casing to.

prevent upward movement of the casing extensionis positioned between rubber 14 and a connecting pipe 16 which extends upward- The slip structure below the packing rubber comprises a sleeve 17 slidable on shell 13 and recessed at its upper endas shown at 18 wardly in back of the slips.

for abutment of the rubber 14. The sleeve tapers downwardly to form a wedge, and its downward movement on shell 13 is limited by its abutment against a shoulder 19 formed thereon.

A slip support 20 is slidable on shell 13 below the wedge, and slips 21 extending upwardly from the support and provided with teeth 22 are expanded for engaging the wall of easing 1 by movement of wedge 17 down- Outwardly bowed springs 23, fixed at one end to the slip support, are adapted to frictionally engage the wall of easing 1 so as to tend to hold the slip support against axial displacement; and a locking engagement between the slip support and shell 13 provides for either dependent axial movement of these parts against the holding tendencyof the springs, or sliding movement of the shell through the slip support when the locking engagement is released.

The releasable locking engagement preferably comprises gudgeons 24 projecting from shell 13, and adapted either for engagement in the recessed ends 25 of circumferential slots 26 formed by hooks 27 depending from the slip support, or adapted for disengagement for the upper end of therubber. A

sleeve 27 is fixed to and projects upwardly from the slip support, with a sleeve 28 slidably mounted on the upper end of sleeve 27 and limited in its relative axial and turning movement by lugs 29 on sleeve 27 received in elongated slots 30 in sleeve 28. The sleeve 28 is connected to the pipe 16 which extends upwardly to the cage 9.

Slips 31 are positioned between the slip support 25 and sleeve 27, with their lower ends forming lugs 32 received in slots 33 in the slip support, and their upper ends form ing teeth 34 which normally lie below a tapering wedge 35 formed at the lower end of sleeve 28. The slips are expanded for en gaging the wall of easing 1 by movement of wedge downwardly inback of the same when sleeve 28 is lowered relative to the slip support. An annulus 36 depends from sleeve 28 and is received over the. slips so that elevation of sleeve 28 relative to the slip support will not only disengage wedge 35 to permit contraction of the slips, but will positively contact the slips by the movement of the annulus along the same.

The teeth of slips 21 and 31 extend in opposite directions as shown in Fig. 1, so\ that engagement of the respective slips with the wall of the casing will hold the casing extension against axial movement in both the wall of easing l.

\Vedge 17 is in non-engagement with slips- 21' so as not to expand the latter to locking engagement in the well casing; and the weight of the packing means shifts the same relative to sleeve 28 so that wedge 35 is also in non-engagement with its cooperating slips 31. The slips 31 are thus free for contraction by annulus 36 so as not to lock in the well casing. Springs 23 tend to frictionally engage the casing wall but the weight of the casing extension lowers the same to the desired level against the holding tendency of the springs.

When the device has been lowered so that pipe 15 projects into the oil sand the desired distance below casing shoe 3, tubing 6 is turned so that the abutment of gudgeons 4 against the walls of recesses 12 turns cage 9 and thereby rotates shell 13 relative to slip support 20 which is held against both axial and rotary displacement by the springs 23.

Gudgeons 24-are thus released from slots 26 so that further lowering of the string of tubing will shift shell 13 downwardly through the slip support 20 as shown in Flg. 2. Slips 21 are thus expanded by wedge 17 to engage the casing wall and lock the wedge against further downward movement, and continued lowering of the string of tubing will thus shift shell 13 downwardly relative to the wedge. soas to axially compress rubber 14 between shoulders 1826 and thereby radially bulge the rubber for tight packing engagement with the wall of easing 1.

Shell 13 is thus locked against further lowering in the well casing, so that a still further lowering of the string of tubing 6 will slide sleeve 28 downwardly on sleeve 27 in order to wedge slips 31 against the Casing wall and thereby lock the casing ex- ,tens'ion against upward movement in the well easing.

Pipe 15 is thusheld against axial displacement in either direction, and a ti ht packing is provided between the pipe an casing so that gas from the oil sand cannot rise directly through the casing but must enter pipe 15 and thus force the oil into the pipe and upwardly through the bore of the well.

When the casing extension is to bewithdrawn, cage 9 is elevated in suitable manner. Sleeve 28 is thus shifted upwardly on sleeve 27 for releasing slips 31 and retracting the same by annulus 36. The abutment of lugs 29 against the ends of slots 30 will then elevate shell 13 relative to slip support 20 until shoulder 19 abuts against wedge 17, the ele vation of the shell relieving the axial pressure on packing 14 so that it may return to normal position spaced from the casing wall. The abutment of shoulder 19 against the .0 wedge 17 will then disengage the wedge from slips 21 so that the slips are released from looking engagement with the casing wall. The parts. are then again in the position shown in Fig.1 with the packing rubber and the locking slips spaced from the wall of the casing so that the casing extension may be freely withdrawn from the well.

I claim: 1. An extension adapted for introduction into a well casing, and means for locking the extension against axial displacement in elther direction b lowering the extension relative to the locking means.

2. An extension adapted for introduction into a well casing, slips having teethadapted to positively engage the wall of the casing v for locking the extension against axial displacement in either direction, and means for forming a tight packing between the casing .and the extension operated by engagement of the slips. i

3. An extension adapted for introduction into a well casing, means forlockin r the extension against axial displacement 1n either direction by lowering the extension relative to the locklng'means, and means for'releasing said locking engagement.

4. An extension for a well casing adapted to receive a string of well tubing, and'means \on one of the couplings which connect lengths of the string of tubing for lowering the extension into the casing by the string of tubing with the latter projecting downwardly through the extension.

5. An extension for a well casing adapted to receive a string of well tubing, means for engaging the extension by the string of tubing for lowering the extension into the eas- -ing, and means for locking the extension against axial movement in either direction "in the casing by lowering the extension relative to the locking means, said engaging means between the extension and tubing being adapted for disengagement to permit movement of the tubing through the exten for releasing the slips and the packing engagement.

7. An'extension for a well casing adapted to receive a string of well tubing, means for engaging the extension by the string of tubing for lowering the extension into the easing, means for locking the extension against axial displacement in either direction by lowering the extension relative to the looking means, means for forming a tight packing between the casing and the extension by said lowering of the extension relative to the locking means, said engaging means between the tubing and the extension being adapted for disengagement to permit movement of the tubing through the extension when the lattenis locked in the casing, and means for releasing the locking and packing engagements between the extension and easing.

8. The combination'of an extension for a well casing, a string of tubing extending therethrough, said string comprising lengths of tubing and collars havinghollow bores and threaded at their ends to engage cooperating threaded ends of next adjacent lengths of the string of tubing, means for locking the extension in the casing, and means on one of said'coupling collars of the string of tub-.. ing for engaging the casing extension to actuate the locking means.

9. An extension adapted for introduction into a well casing, and normally inoperative slips having teeth. adapted to positively engage the wall of the casing for locking the extension against axial displacement in ei- 100 ther direction, said slips being operated by lowering the extension relative to the slips.

10. An extension adapted to be received in-a well casing, packing on said extension,

a member slidable on the extension and .adapted to engage the packing for expanding the same to form a tight packing between the extension and the well casing, and means actuated by longitudinal movement of the extension relative to said means for sliding said member and locking the extension against axial displacement in either direction in the casing.

11. A conduit adapted to be received in a well easing, means for locking the conduit against downward movement in the well casing by lowering the conduit relative to the locking means, slips on the conduit, and a member adapted to telescope relative to the conduit and expand the slips for locking 120. the conduit against elevation in the well casing. V1

"12. A conduit adapted for introduction into a well casing means for locking thecon- 'duit against axia displacement in either dia Well casing, packing on said extension, a member slidable on the extension and adapted to engage the packing for expanding the same to form a tight packing between the extension and the well casing, and means actuated by lo'ngitudina-lly movement of the extension relative to said means for sliding said member and locking the extension against downward movement in the well casing, slips on the extension, and a member adapted to telescope relative to the extension and expand the slips for locking the extension agziinst elevation in the Well casing.

Intestimony whereof I have aifixed my signature to this specification.

ERD V. CROl/VELL. 

